Investigators released surveillance video of the suspect on Wednesday. The crime happened around 11:40 a .m. on Wednesday, January 18th.
Police believe it may have been an inside job, saying the suspect knew where he was going and was in and out of the building within just a few minutes.
According to police, the man entered the victim's apartment in the 29th floor of the Dorchester building after entering through a construction zone on Locust Street.
"He knew where he was going and we believe he had prior knowledge. This was not a random act," said Lt. Pat Dougherty of the Philadelphia Police.
While inside, the suspect took various pieces, mostly gold rings, from an elderly woman who collects jewelry.
The thief then fled the apartment, police say, went down the elevator and exited the rear of the building back onto Locust.
The suspect is described as a 30-year-old black male standing about six feet tall with a large build. Police say he was wearing a green or blue jacket, a dark knit colored hat and dark colored jeans.
Residents of this tony Center City neighborhood say the bustling area can be ideal for thieves to go unnoticed.
"It's unfortunate in this day and age that we do need security in these high rises," said Louise Littman.
"Somebody informed on that women's collection. What can I say, that's why you have to be so careful about whom you admit in your apartment," said Florence Hanker.
"If you know a loved one is getting up in age, you should take some steps to safeguard these heirlooms, to not leave them in an apartment where these types of things can happen," said Lt. Dougherty.
Police ask that anyone with information dial 911, the police tipline at 215-586-TIPS (8477) or through phillypolice.com.